Topeak mount brackets xlquick and easy to install topeaks mount brackets xl have been designed for small bicycle frames 34 5cm long you can enjoy peace of mind when fitting your babyseat ii racks or mtx tubular racks featureseasy to installlightweightstrongsecure fittingmanufacturers noteif you have a small frame bicycle which cannot fit a topeak rack or babyseat in the recommended position of 2 or 3 from horizontal please use the 34 5cm extra long mounting bracket arm for secure ins